I have a large inground pool, around the 40000 gals. size, with a sand filter.
I use untreated well water for filling and it has iron content that is staining our older vinyl liner.

I had used the CuLator Ultra eliminator before, but cannot find it online for purchase in Ontario.
And shipping costs from the US make it too expensive.

From your ordering page, it appears that you will ship Ferri-Iron tablets to Ontario for $6.50 USD.
Is that correct? If so, this should solve my problem.